supported by the Model 135 ICA:
• Terminal Adapter Type I Model II 1050 Data communication System
2740 Communication Terminal (Models 1 and 2) and 2760 Optical Image Unit 2741 Communication Terminal
System/7
• Terminal Adapter Type III
2845 Display Control and 2265 Display Stations
2848 Display Control (Models 1, 2, and 3) and 2260 Display Stations (Mode Is 1 and 2)
• Synchronous Data Adapter Type II
Another System/360 or System/370 with a 2701 Data Adapter Unit or 2703 Transmission Control
Another System/370 Model 135 with the ICA and Synchronous Data Adapter Type II feature
System/3 (Model 6 and Model 10) with the Binary Synchronous Communications Adapter
Model 20 with the Binary Synchronous Communications Adapter Model 25 with the ICA and Synchronous Data Adapter
1130 System with the Synchronous Communications Adapter 1800 System with the Communications Adapter
2770 Data Communication System 2780 Data Transmission Terminal
2790 Data Communication System (via 2715-2) 3735 Programmable Buffered Terminal
In addition to the above, the 2701 supports 1030, 1060, and 1070 communication systems, ATiT 83B2/83B3 terminals, WU 115A terminals, and TWX-33/35* terminals. While these systems and terminals cannot be attached to the Model 135 via the ICA, they can be attached via the byte multiplexer channel and a 2701, 2702, or 2703 transmission control unit. (The Model 25 ICA supports the same terminals as the 2701 except for the 2260 and 2265 Display stations and is functionally compatible with the 2701 when DOS BTAM is used.)
The terminal adapter features for the Model 135 ICA are functionally equivalent to their 2701 counterparts, as far as support provided is concerned, with a few exceptions as outlined below. Variations in
actual implementation between Model 135 ICA and 2701 equivalent adapters are handled by the telecommunications access methods and these are
transparent to the user when these access me~~ods are used. The Model 25 ICA is compatible with the Model 135 ICA for the same functions for Which the Model 25 ICA is compatible with the 2701.
See System/370 Model 135 Functional Characteristics for specifics about the CPU interference caused by operations on the ICA.
ICA Feature Equivalent to 2701 Terminal Adapter ~
!
Model II This basic adapter feature is used for communication with a 1050 system, a 2140 ter~inal, a 2141 terminal without the Interrupt feature, or a System/7 and uses a processor-clocked modem. A data rate of up to 600 bits per second is supported.Write Interrupt is an optional feature for this adapter that allows a terminal operator to interrupt a transmission from the Model 135.
This feature, not available on the 2701, is compatible with the 2741 Break feature on the 2702 and 2703 that supports a 2741 with the Interrupt feature. Read Interrupt, not available on the 2701 or the
* Terminals which are equivalent to those explicitly supported may also function satisfactorily. The customer is responsible for establishing equivalency. IBM assumes no responsibility for the impact that any changes to the IBM-supplied products or programs may have on such terminals.
24
Model 25 ICA, is another feature for this adapter. It permits an executing program in the Model 135 to interrupt a transmission from a terminal as does the Type I Terminal Interrupt feature on the 2102 and 2103.
ICA Feature Equivalent to 2101 Terminal Adapter ~ III
This feature is used for communication with remote 2848 Display Control and 2260 Display Stations or remote 2845 Display Control and 2265 Display stations. Either a processor-clocked modem with a data rate of 1200 bits per second or a self-clocking modem with a data rate of 2400 bits per second can be used.
ICA Feature Equivalent to 2101 Synchronous Data Adapter ~ II This feature is used for communicating with any terminal or IBM computer that conforms to the Binary Synchronous Communication standard defined in General Information - Binary Synchronous Communications
(GA21-3004). Data rates of 600 or 1200 bits per second with a
processor-clocked modem and any data rate up to 4800 bits per second with a self-clocking modem are supported. (The 2101 supports up to 230,400 bps and the Model 25 ICA handles up to 4800 bps.)
The communication network can be point-to-point or centralized multipoint. There is no provision for noncentralized multipoint operations (supported by the 2101) and the Model 135 ICA rejects a SEARCH command. In a centralized multipoint operation, each line can be either a control station or a tributary station. The control station feature is standard and if a line is to have the tributary feature
instead, this must be specified when the ICA is ordered.
A line that is flagged as a control station operates in the same way as a 2101 Synchronous Data Adapter without the associated Station Selection facility. A line that is flagged as a tributary station operates in the same way as a 2101 Synchronous Data Adapter with the associated Station Selection facility, and will reject a POLL command.
The Autoanswer feature is available for the Model 135 ICA, but the Autocall feature (DIAL command), available for the 2101 and the
Model 25 ICA, is not.
Each binary synchronous line connected to the ICA can use anyone of three data code options: EBCDIC, ASCII, or Six-Bit Transcode.
Optionally, a line can have the Dual Code feature and/or the Transparent Mode feature (features also available on the 2101 and the Model 25 lCA).
The Dual Code feature permits one of the three possible data code options to be used as an alternative code for the line. The line uses the primary code assigned unless the alternate code is made effective by issuing a SET MODE. The Transparent Mode feature provides for the transmission of all possible bit patterns within the selected code level. Binary synchronous lines attached via the ICA can have data code features different from one another, if desired.
SELECTOR CHANNELS
Optionally, one or two selector channels can be installed on the Model 135 in addition to the optional Integrated File Adapter.
Selectors are addressed as channels 1 and 2 when the IFA is not installed and as channels 2 and 3 when the IFA is present. Data is
transferred between processor storage and the four-byte buffer in each channel, one or two bytes at a time, using cycle stealing. Single-byte transfers occur when the first or last Single-byte of a data block is on an odd storage address, for example.
Selector channels on a Model 135 are functionally equivalent to System/360 selector channels but support significantly higher data rates than Model 30 channels. The maximum data rate that can be when this maximum channel activity occurs.
A Model 135 I/O device configuration can include direct access storage on both selector channels if the IFA is not installed. When the IFA is present, direct access storage can be placed on only one of the two possible channels and the channel selected must have the higher priority for command chaining operations.
The normal priority for command chaining channel operations is (high to low) first channel (channel 2): I FA: second channel (channel 3).
The no-charge Channel Priority feature, if installed, reverses the priority of the two channels for command chaining operations, which
The following summarizes the I/O device configurations possible on the Model 135. The first channel has the highest priority for command chaining operations. If the Channel Priority feature is installed, the I/O devices indicated for the first channel in